Sun visors for vehicle are known in the art which comprise a body or screen, rotatably mounted over a shaft attachable to the vehicle structure. The screen can be a doubled shelled structure (two shells assembled to constitute the structure and the external shape of the screen, sometimes twin shells) or an skeleton structure (the structure is done by a plastic part, sometimes enhanced with a wireframe, and coated externally with two foams). The plastic part structure can be a single piece or constituted by more than one piece. The screen can be a plastic or a cardbox screen. The screen can be upholstered.
The user (driver) folds down the sun visors screen (when needed) to a position which prevents the glare. This position must be adjustable in regard to the relative position of the sun and the eye of the driver. In the selected position, the user can release the screen and the position must be maintained, whichever the vibrations given by the running car. To maintain this position, a friction torque must be applied between the screen and the shaft. This friction torque is generated by a metallic pincer (detent spring clip), generally hold in the screen. The detent spring is fixed to the screen and elastically engaged over the shaft such that when the screen is rotated the detent spring rotates around the shaft, generating the friction torque.
At the same, when the sun visor is of no use, the user can fold it up against the headliner. In this situation, the detent spring clip encounters a flat surface, generated on the shaft, and by clamping on the edge of the flat surface, it generates a fold-up torque which automatically folds-up the screen against the headliner (and prevents the screen form vibrating and generating noise).
Sun visors with a slide on rod function (to covert the most lateral glares) comprise a slider mounted to the shaft so that the slider can slide longitudinally in a pathway generated in the structure of the screen. The slider holds the detent spring clip which clamps the shaft such that the shaft can rotate inside the detent spring clip (the detent spring clip is fix in rotation relative to the slider and the screen) and generates the torques and detent forces, but is fixed longitudinally on the shaft. When pulling the screen, the screen slides longitudinally over the slide, but that way the weight of the sunvisor rests upon the edge of the shaft such that, if the engagement between the shaft and the screen is not strong enough the vibrations produced by the vehicle are transmited to the sun visor which can move excessivelly and even enter in resonance.
The sun visor usually comprises a guiding hollow structure or guiding profile (sometimes a tube) mounted in a pathway of the screen of the sun visor to improve the sliding between the slider and the screen. The slider usually slides inside the tube.
A problem in the art is that for establishing the inoperative position of the sun visor the detent spring clip must cooperate with a flat surface of the shaft. For that reason the detent spring clip is usually an asymmetric spring with a longer side for friction over the rounded surface of the shaft and a smaller side for attaching upon the flat surface (the width of this flat surface is adapted to the detent spring clip size) so that the force to change from one position to the other is not too high. As the detent spring clip is not symmetric it must be mounted over the shaft in the right position/orientation to establish correctly the two positions for the sun visor. The detent spring clip must be installed in one and only one direction (it can't be installed in an opposite way). If the détente spring clip is mounted with the wrong orientation the flat surface effect would not append at the proper angle (it will completely disturb the fold-up torque and angle).
Furthermore the guiding profile is usually symmetrical, which means that it can be installed inside the structure (skeleton or double shelled) in both directions, in a right or wrong position.
The slider itself can also be introduced inside the guiding profile in both sides, too, which means that the correct position/orientation of the detent spring clip must be checked and confirmed during the assembly operations.
The above difficulty is increased by the fact that the vehicles have (practically) always two symmetrical sun visors; one left hand side sun visor and one right hand side sun visor. The main components of these sun visors are symmetrical, too (double shells, skeleton, shaft, etc. . . . ) which means that it is possible to install a left hand slide on rod device in a right hand sun visor in a right or wrong position.
Sun visors with a slide on rod function are disclosed for example in U.S. Pat. No. 8,434,811-B2, U.S. Pat. No. 8,845,000-B2, U.S. Pat. No. 8,333,422-B2, and U.S. Pat. No. 7,798,552-B2.